/*
 * Copyright (C),2015,北京新诺创科软件技术有限公司
 * author zhangmengliang
 */
package com.xnck.mfpms.util;


import java.security.MessageDigest;

/**
 * MD5加密工具
 */
public class MD5Utils {

    private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9",
            "a", "b", "c", "d", "e", "f" };

    /**
     * 以UTF8格式对字符串进行MD5加密
     * @param origin
     * @return
     * @throws Exception
     */
    public static String MD5Encode(String origin) throws Exception {
        String resultString = MD5Encode(origin,"UTF-8");
        if(null != origin && !"".equals(origin)){
            return resultString.toUpperCase();
        }
        return resultString;
    }

    /**
     * MD5加密字符串
     * @param origin 被加密的字符串
     * @param charsetname 字符串编码
     * @return
     * @throws Exception
     */
    public static String MD5Encode(String origin, String charsetname) throws Exception {
        String resultString = null;
        try {
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (null == charsetname || "".equals(charsetname)){
                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
            }
            else{
                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
            }
        } catch (Exception e) {
            throw e;
        }
        return resultString;
    }

    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++)
            resultSb.append(byteToHexString(b[i]));

        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0)
            n += 256;
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }
}
